Electron tube and socket having overlapping terminals and contacts and interengaging holding means



l g- 1966 P. D. WILLIAMS ETAL 3,257,314

ELECTRON TUBE AND SQCKET HAVING OVERLAPPING TERMINALS AND CONTACTS AND INTERENGAGING HOLDING MEANS Filed March 26, 1962 2 Sheets-Sheet 1 IN VEN TORS PAUL D. WILLIAMS 9 BY WILLIAM A. ALLEN M0231 ATTORNEY g- 1966 P. D. WILLIAMS ETAL 3,257,314

ELECTRON TUBE AND SOCKET HAVING OVERLAPPING TERMINALS AND CONTACTS AND INTERENGAGING HOLDING MEANS Filed March 26, 1962 2 Sheets-Sheet 2 INVENTORS PAUL D. WILLIAMS WILLIAM A. ALLEN ATTORNEY United States Patent M 3,267,314 ELECTRON TUBE AND SQCKET HAVING OVER- LAPPING TERMINALS AND CONTACTS AND INTERENGAGING HOLDING MEANS Paul D. Williams, Portola Valley, and William A. Allen, Belmont, Califi, assignors, by mesne assignments, to Varian Associates, a corporation of California Filed Mar. 26, 1962, Ser. No. 182,467 11 Claims. (Cl. 313-49) This invention relates to electron tubes and more par ticularly to an improved terminal arrangement for tubes and cooperating socket structure.

It has been proposed in the past to provide terminals on a tube in the form of axially spaced continuous rings of successively decreasing diameter. One of the reasons for this type of terminal is to provide increased terminal area and therefore increased current carrying capability, as distinguished from pin or tab type terminals. In most cases the socketing structure for such tubes involves ringtype contact fingers engaging the peripheral edges of the terminal rings. Another socketing arrangement suggested in the past has been to provide the socket with continuous rings which overlap the terminal rings and make contact along an annular surface on the face of the terminal rings. Although the latter arrangement has several desirable features it has not been widely adopted because of the difficulty of providing a practical means for inserting and holding the tube in the socket.

It is an object of this invention to provide an electron tube which obtains the benefit of ring-type terminals and yet has a simple and effective means for inserting and holding the tube in a socket.

Another object of the invention is to provide an electron tube of the type described in which the means for inserting and holding the tube in a socket does not materially add to the outside dimensions of the tube.

A further object of the invention is to provide electron tubes of the type described in which the means for inserting and holding the tube in a socket is easily adaptable to various types of tubes.

An additional object of the invention is to provide an improved electron tube socket which cooperates with improved tubes which meet the preceding objectives.

Another object of the invention is to provide an improved tube and socket assembly of the type described in which efficient cooling of the tube is possible.

By way of brief description an improved tube according to the invention comprises a terminal end having a side wall formed by continuous terminal rings separated by insulating cylinders. The terminal rings project outwardly of the insulating cylinders and are of successively increasing diameter, starting with the smallest diameter adjacent the end of said terminal end. The means for inserting and holding the tube in the socket comprises a locking arrangement at said terminal end. The socket comprises contact rings which cooperate with the terminal rings on the tube and a locking arrangement which cooperates with the locking arrangement on the tube, all as will be hereinafter described in detail.

Other and further objects and features of advantage will be apparent from the following detailed description which makes reference to the accompanying drawings in which:

FIGURE 1 is a cross-sectional view of a tube and socket embodying the features of the invention,

FIGURE 2 is a bottom view of the tube in FIGURE 1,

' on a greatly reduced scale,

FIGURE 3 is a cross-sectional view similar to FIGURE 1 but showing the invention embodied in a different tube, and

3,267,314 Patented August 16, 1966 FIGURE 4 is a side view of the locking member on the socket of FIGURE 3.

Referring in more detail to the drawings, FIGURE 1 discloses a generally cylindrical tube 1. The lower end of the tube is the terminal end and has a side wall formed by metal terminal rings 2-5 separated by short ceramic cylinders 6-9. The terminal rings are of successively increasing diameter starting with the smallest ring 2 up to the largest ring 5. The end wall at the terminal end of the tube is formed by a metal disk 10 which is attached to ceramic cylinder 6. It will be noted that disk 10 is cone-shaped or recessed toward the anode for reasons to be hereinafter described.

Above ring 5 the tube envelope is formed by a ceramic cylinder 11 and an inverted cup-shaped metal anode 12. Thin metal sealing rings 13 and 14 are attached to the members 11 and 12 and the final seal is formed by welding or brazing at 15. Conventional cooling fins 16 are attached to the side of the anode, and a conventional pinch-off tubulation 17 is attached to the top of the anode. As is common in the art, the ends of all of the ceramic cylinders are metalized and brazed to the adjacent metal parts.

The tube contains a conventional cylindrical cathode can 20 surrounded by a conventional wire cage type control grid 21 and a similar screen grid 22. Metal support cylinders 23, 24 and 25 connect the cathode and grids to the terminal rings 3, 4, and 5, respectively. The .cathode is heated by a wire coil 27 which is connected at one end to a support pin 28 mounted on terminal ring 2 by means of thesupport portion 29. The other end of the heater 27 is mounted on a support post 30 which is brazed in a central aperture in the end wall 10.

Post 30 extends below wall 10 to provide a downwardly projecting threaded portion 31 which can be integral with post 30 or a separate piece brazed to the post. In either case, portion 31 has its rim 32 brazed to wall 10. Thus it will be seen that post 30 and portion 31 are connected to wall 10 at two axially spaced positions to provide a very rigid structure. Threaded portion 31 provides the tube element which cooperates with the socket to pull the tube into the socket and hold it there. Since threaded portion 31 is located at the end and on the axis of the tube it does not increase the outside diameter of the tube at all, nor can it possibly interfere with flow of cooling air along the side wall of the tube. Also, since a part of threaded portion 31 fits within the recess formed by the end wall 10, it adds only a relatively small amount to the length of the tube.

FIGURE 1 shows tube I mounted in a generally cylindrical socket 40 comprising a metal base portion 41 and four metal contact rings 42-45. These metals parts are spaced apart by four insulating parts of dielectric material such as ceramic. The base insulating part is a cupshaped member 46 having a countersunk central bore 47 providing a shoulder 48. Base member 41 is shaped to match the countersunk bore 47, and is brazed or otherwise secured therein. The other three insulating parts are short cylinders 49-51 which separate the contact rings 42-45. Electrical contact can be made to rings 42-45 where they project outwardly of the insulting cylinders 49-51. The metal rings 42-45 and the insulating members 46, 49-51 can be conveniently assembled by a plurality of circumferentially spaced bolts 52.

In order to obtain insertion of the tube in the socket and hold it there, the base portion 41 is provided with internal threads 53 which match the external threads on the tube member 31. Cooling is made possible by means of circumferentially spaced holes 54-58 in members 46, 42, 43, 4, and 5, respectively. Thus, cooling air forced against the bottom of the socket will flow along the side wall of the tube through the holes 54-58.

FIGURE 1 discloses a tube of relatively small size such that the external rim around cooling fins 16 can be grasped by the fingers of one hand. Thus it is a simple matter to insert the tube in the socket until its threaded member 31 engages the base portion 41 of the socket and then rotate the tube so that the interengaging threads will draw the tube into the socket until end wall of the tube is drawn tight against base portion 41 of the socket. The threads are thus stressed tightly together to provide a friction force preventing accidental loosening of the tube.

It will be appreciated that excellent electrical contact is assured between terminal rings 2-5 and contact rings 42-45 for two reasons. One reason is that the tube and socket parts are designed so that the overlapping contact and terminal rings engage each other before the end wall 10 of the tube bottoms out against base portion 41 of the socket. Thus, during insertion the terminal and contact rings experience a rotating or Wiping contact therebetween which cleans the rings and assures good contact. Since the contact rings on the socket are engaged by the tube terminal rings prior to full insertion of the tube it will be appreciated that the contact rings 42-45 are deflected downwardly from their normal free positions. Thus, in addition to the wiping contact during insertion, the rings are stressed into tight contact after the tube has been fully inserted in the socket. Contact rings 42-45 on the socket are preferably made of weaker or thinner material than the terminal rings on the tube so that substantially all of the deflection will be experienced by the socket rings rather than the tube rings, for the reason that deflection of the tube rings might damage the hermetic seals between the tube rings 2-5 and the adjacent ceramic cylinders.

Obviously it is imperative that the outside diameter of terminal ring 2 be greater than the inside diameter of contact ring 42 in order to obtain overlapping contact between these rings. At the same time it is also imperative that the outside diameter of ring 2 be less than the inside diameter of every contact ring above contact ring 42 so that ring 2 can pass through all of the contact rings above ring 42. Similarly, the outside diameter of each of the terminal rings 3, 4 and 5 must be larger than the inside diameter of the contact ring it engages in FIGURE 1 and smaller than the inside diameter of every contact ring above the one it engages.

FIGURE 3 discloses the invention embodied in a tube 60 which differs in many respects from the tube in FIG- URE 1 and thus portrays the facility with which the invention can be adapted to different types of tubes. For example tube 60 does not have the same internal structure as tube 1. In addition tube 60 has substantially larger physical size as indicated by the following chart:

Tube 60 is a generally cylindrical structure in which the lower end of the tube is the terminal end and has a side wall formed by metal terminal rings 62-65 and short ceramic cylinders 6669. The terminal rings are of successively increasing diameter starting with the smallest ring 62 up to the largest ring 65, The end wall at the terminal end of the hermetically sealed tube envelope is formed by a metal disk 70 in cooperation with other structure which will be hereinafter described.

Above ring 65 the tube envelope is formed by ceramic rings or cylinders 73-77, sealing flanges 78-8-1, and a metal anode 82 having a metal mounting flange 83. Conventional cooling fins 86 are attached to the side of the anode, and a conventional pinch-oft tubulation 87 is attached to the top of the anode. The reason for the ceramic rings 73, 74, 75 and 77 is to strengthen the ceramic to metal brazes, and as is conventional, rings 74 and 75 are preferably not brazed to each other, nor is ring 77 brazed to metal flange 83. The sealing rings are brazed or welded at 88. As in the case of tube 1, all the ends of the ceramic cylinders or rings, with the exceptions previously mentioned are metalized and brazed to the adjacent metal parts.

The tube 60 contains a conventional filamentary directly heated type cathode made of hairpin wires 91. The cathode is surrounded by a conventional wire cage type control grid 92 and a similar screen grid 93. Metal support cylinders 94 and 95 connect the grids 92 and 93 to the terminal rings 64 and 65, respectively. The cathode is supported by two metal cylinders 96 and 97 connected to terminal rings 62 and 63, respectively. Cylinders 96 and 97 are slotted at their upper ends to form interdigital fingers 98 and 99, respectively. Thus, the lower ends of each hairpin wire are arranged so that one is connected to a finger 98 and the other is connected to a finger 99. The upper end of each hairpin wire is looped over a radial projection on a disk 102 carried by an insulating sleeve 103. Sleeve 103 is guided on a center post 104 for axial sliding movement thereon. Sleeve 103 is attached to one end of a tubular member 105 which carries an inverted cup 106 on its other end. Cup 106 is central- 1y apertured to be freely slideable on post 104.

As previously stated, the lower end wall of the hermetic envelope of tube 60 is formed in part by disk 70. The remainder of the end wall is formed by a thick metal disk 107 brazed in cylinder 96 and by the portion 108 of cylinder 96, which portion extends below disk 107 and is brazed to disk 70. Thus, it will be noted that electron tube 60 also has an end wall structure which is recessed toward the anode to accommodate the locking means to be hereinafter described.

It is old in the art to provide tensioning means for a filamentary cathode such as cathode 90. The means herein for accomplishing the tensioning comprises a compression spring 110 which abuts cup 106 and disk 107. Thus, the cathode top disk 102 is forced upwardly by spring 110 and serves to tension the hairpin wires 91 because the bottom ends of the Wires are held in fixed position by the fingers 98 and 99.

The upper end of post 104 projects through top plates 111 and 112 On grids 92 and 93 respectively. A ceramic sleeve 113 is brazed to post 104 and to plates 111 and 112. Thus post 104 is rigidly held at the top by grid cages 92 and 93 and at the bottom by disk 107 in which it is securely brazed.

The locking means for tube 60 comprises a metal plate made of two pieces 116 and 117 brazed together. The reason for two pieces is that strength is required but only the thinner upper piece 117 can be brazed to ceramic without cracking the ceramic. Piece 117 is brazed to a ceramic ring 118 which is in turn brazed to end wall 70. If piece 117 were brazed directly to Wall 70, the combined metal thickness would crack ceramic 66. An extra ceramic ring 119 is brazed to piece 117 to prevent cracking of ceramic 118. The locking means on tube 60 comprises a sleeve 120 which is brazed in central apertures in pieces 116 and 117. The sleeve 120 has a pin 121 brazed therein and extending diametrically across the sleeve.

FIGURE 3 shows tube 60 mounted in a generally cylin drical socket comprising a metal base portion 141 and four metal contact n'ngs 142145. These metal parts are spaced apart by four insulating parts of dielectric material such as ceramic. The base insulating part is a cup-shaped member 146 having a central bore 147. Base portion 141 fits across bore 147 and is connected to member 146 by a plurality of bolts 148. The other insulating parts are short cylinders or rings 149-151 which separate the contact rings 142-145. Electrical contact can be made to rings 142-145 where they'project outwardly of the insulating rings 149-151. The metal rings 142-145 and the insulating rings 146, 149-151 can be conveniently assembled by a plurality of circumferentially spaced bolts 152.

In order to obtain insertion of the tube 60 in the socket 140 and hold it there, the base portion 141 is provided with a centrally located cylinder 153, as indicated in FIGURES 3 and 4. It will be understood that cylinder 153 as shown in FIGURE 4 is rotated slightly from its position in FIGURE 3 in order to present a clearer view of its groove configuration. Cylinder 153 is attached to base portion 141 by means of bolts 153'. Cylinder 153 is provided with symmetrically opposite cam grooves 154 and 155 on opposite sides thereof. Each of the grooves has a vertical inlet portion 156, a sloping side portion 157, a horizontal end portion 158, and a holding arc 159 at the tip of the end portion 158.

As in the case of FIGURE 1, cooling of the structure of FIGURE 3 is made possible by means of circumferentially spaced holes 160-164 in members 146, 142, 143, 144, and 65, respectively. It is also possible of course to make the socket contact rings 142-145 so that instead of being solid rings the inner periphery of each ring is formed by closely spaced inwardly projecting contact fingers. If the latter structure is used, cooling air can flow through the spaces between the contact fingers.

As previously explained, tube 60 is of such Weight and size that holding it for insertion into the socket requires both hands. Thus it is not practical to use the threaded locking means of FIGURE 1. The substantial top heavy weight of tube 60 combined with the required two-hand grip would make it difficult to engage threads and rotate the tube without damaging the threads. However, the locking means of FIGURE 3 is a very practical arrangement for tube 60. In order to socket tube 60, it is grasped with both hands and lowered into the socket until sleeve 120 on the tube slides over cylinder 153 on the socket thus centering the tube in the socket. The lowering of the tube is continued until pin 121 on the tube rests on the upper rim of the socket cylinder 153. It is then a simple matter to rotate the tube until pin 121 enters the inlet portion 156 of each of the cam grooves 154 and 155. The tube then drops straight down making initial contact between terminal rings 62-65 and contact rings 142-145. Then the tube is rotated so that pin 121 is cammed down along groove portions 157. This provides the wiping and stressing action between the terminal and contact rings. The holding arcs 159 prevent accidental loosening of the tube. Intended removal of the tube is accomplished by pushing down on the tube to release pin 121 from arcs 159 and then rotating the tube so that pin 121 moves back along groove portions 157. The relative strengths and dimensions of the rings 62-65 and 142-145 are the same as described for rings 2-5 and 42-45 in FIGURE 1.

We claim:

1. A generally cylindrical electron tube comprising an anode at one end of the tube, a plurality of other electrodes in the tube, the other end of said tube being the terminal end and having a side envelope wall comprising disk-shaped circular terminal rings separated by insulating cylinders, support means connecting said terminal rings to said electrodes inside said tube, said terminal rings projecting outwardly from said insulating cylinders and having successively decreasing diameters starting with the largest diameter ring adjacent said anode end of the tube, and means on the axis of the tube at said terminal end for locking said tube in a socket, said locking means having a smaller diameter than the diameter of the terminal end of said side envelope wall.

2. An electron tube as claimed in claim 1 in which said locking means comprises a screw-threaded member.

3. An electron tube as claimed in claim 1 in which said locking means comprises a locking member having a circular bore therein, and a pin projecting across said bore.

4. A generally cylindrical electron tube comprising an anode at one end of the tube, a plurality of other electrodes in the tube, the other end of said tube being the terminal end and having a side wall comprising diskshaped circular terminal rings separated by insulating cylinders, support means connecting said terminal rings to said electrodes inside said tube, said terminal rings projecting outwardly from said insulating cylinders and having successively decreasing diameters starting with the largest diameter ring adjacent said anode end of the tube, an end wall for the envelope of said tube at said terminal end, said end wall being centrally recessed toward said anode end, and means on the axis of the tube at said terminal end for locking said tube in a socket, said locking means being located at least partially in said recess, said locking means comprising a cam surface arranged at a slope with respect to the axis of the tube, and said locking means having a smaller diameter than the diameter of said side wall at the terminal end of the tube.

5. An electron tube as claimed in claim 4 in which said end wall includes a cylinder coaxial with said tube and a closure member across said cylinder, said closure member being substantially spaced from the end of said cylinder whereby said recess is formed in the end of said cylinder, and said locking means project into the open end of said cylinder.

6. An electron tube as claimed in claim 4 in which said tube includes a center post projecting through said end wall, and said locking means comprises a screw-threaded end on the projecting portion of said post.

7. An electron tube and socket assembly comprising a generally cylindrical tube having an anode at one end, a plurality of other electrodes in said tube, the other end of said tube being the terminal end and having a side envelope wall comprising disk-shaped circular terminal rings separated by insulating cylinders, support means connecting said terminal rings to. said electrodes inside said tube, said terminal rings projecting outwardly from said insulating cylinders and having successively decreasing diameters starting with the largest diameter ring adjacent said anode end of the tube, and said socket comprising a base portion, a plurality of spaced disk-shaped circular contact rings supported one above the other from said base portion, said contact rings having successively increasing inside diameters starting with the smallest inside diameter adjacent said base portion, the outside diameters of said terminal ring and the inside diameters of said contact rings being such that each of said terminal rings overlaps one of said contact rings and has an outside diameter smaller than the inside diameter of the remainder of said contact rings toward said anode end, and locking means on the terminal end of said tube cooperating with locking means on the base portion of said socket to pull said tube and socket together upon rotation of the tube and sockeet relative one to the other, said locking means on the tube having a smaller diameter than the diameter of the terminal end of said side envelope wall.

8. A tube and socket assembly as claimed in claim 7 in which said locking means on the tube component and socket component comprises a locking member on one of said components and having a cam groove therein and sloping with respect to the axis of said tube and socket, and a pin on the other of said components fitting in said groove.

9. A tube and socket assembly as claimed in claim 7 in which said locking means on the tube component and socket component comprises an externally threaded member on one of said components and a locking member on the other of said components having internal threads matching the threads on said externally threaded member.

10. A tube and socket assembly as claimed in claim 7 in which the annular partitions formed by said overlapping terminal and contact rings are provided with apertures for permitting flow of cooling fluid along said side envelope wall.

11. A generally cylindrical electron tube comprising an anode at one end of the tube, a plurality of other electrodes in the tube, the other end of said tube being the terminal end and having a side wall comprising diskshaped circular terminal rings separated by insulating cylinders, support means connecting said terminal rings to said electrodes inside said tube, said terminal rings projecting outwardly from said insulating cylinders and having successively decreasing diameters starting with the largest diameter ring adjacent said anode end of the tube, an end wall for the envelope of said tube at said terminal end, said end wall being centrally recessed toward said anode end, and means on the axis of the tube at said terminal end for locking said tube in a socket, and said locking means having a smaller diameter than the diameter of said side Wall at the terminal end of the tube, said locking means comprising a support plate attached to the terminal end of said tube, a locking sleeve on said plate and projecting into said recess, and a locking pin projecting across said sleeve.

References Cited by the Examiner UNITED STATES PATENTS Gale 339181 Loughridge 31351 X Brush 339182 Howard 33994 Sorg et a1 313-250 X Martin 339-182 Eitel et a1 313250 X McCullough et al. 339190 X Johnstone et a1 339-182 Foote et a1. 31351 Manfredi 313250 X Germany.

. JAMES W. LAWRENCE, Primary Examiner.

20 GEORGE N. WESTBY, Examiner.

C. O. GARDNER, R. SEGAL, Assistant Examiners. 

1. A GENERALLY CYLINDRICAL ELECTRON TUBE COMBINATION AN ANODE AT ONE END OF THE TUBE, A PLURALITY OF OTHER ELECTRODES IN THE TUBE, THE OTHER END OF SAID TUBE BEING THE TERMINAL END AND HAVING A SIDE ENVELOPE WALL COMPRISING DISK-SHAPED CIRCULAR TERMINAL RINGS SEPARATED BY INSULATING CYLINDERS, SUPPORT MEANS CONNECTING SAID TERMINAL RINGS TO SAID ELECTRODES INSIDE SAID TUBE, SAID TERMINAL RINGS PROJECTING OUTWARDLY FROM SAID INSULATING CYLINDERS AND HAVING SUCCESSIVELY DECREASING DIAMETETS STARTING WITH THE LARGEST DIAMETER RING ADJACENT SAID ANODE END OF THE TUBE, AND MEANS ON THE AXID OF THE TUBE AT SAID TERMINAL END FOR LOCKING SAID TUBE IN A SOCKET, SAID LOCKING MEANS HAVING A SMALLER DIAMETER THAN THE DIAMETER OF THE TERMINAL END OF SAID SIDE ENVELOPE WALL. 